Short-term effects of barefoot and simulated barefoot running have been widely discussed in recent years. Consequences of adopting barefoot running for a long period, including as a training approach, still remain unknown. The present study evaluated the influence of 16 weeks of progressive barefoot running training on impact force and muscle activation in habitual shod runners. Six habitual shod runners (3 men and 3 women, 29.5 ± 7.3 years) were tested barefoot (BF) and shod (SH), before and after 16 weeks of progressive barefoot running training...

BACKGROUND: To investigate the association between running exposure and the risk of hamstring strain injury (HSI) in elite Australian footballers. METHODS: Elite Australian footballers (n=220) from 5 different teams participated. Global positioning system (GPS) data were provided for every athlete for each training session and match for the entire 2015 season. The occurrences of HSIs throughout the study period were reported. Receiver operator characteristic curve analyses were performed and the relative risk (RR) of subsequent HSI was calculated for absolute and relative running exposure variables related to distance covered above 10 and 24 km/hour in the preceding week/s...

OBJECTIVES: To compare cardiovascular fitness and physical activity of schoolchildren 18 months after London 2012 according to Olympic 'inspiration'. DESIGN: A cross-sectional comparison between groups of schoolchildren categorised according to self-reported Olympic inspiration and a repeated cross-sectional comparison using data collected pre-2012. SETTING: Schools within a 50 km radius of the Olympic Park, Stratford, London. PARTICIPANTS: 931 students (10...

CONTEXT: Post-exercise cardiac troponin release has been extensively described in athletic groups but little attention has been given to any role of sex in mediating this phenomnenon. OBJECTIVE: We compared the release of cardiac troponin T (cTnT) after endurance running in training-experience, biological-age and maturity-matched young male and female runners. MATERIALS AND METHODS: Nineteen male (training history: 2.3±1.0 yr; mean age: 16...

Purpose: To examine the effects of the world's most challenging mountain ultramarathon (MUM, 330 km, cumulative elevation gain of +24,000 m) on the energy cost and kinematics of different uphill gaits. Methods: Before (PRE) and immediately after (POST) the competition, 19 male athletes performed three submaximal 5-min treadmill exercise trials in a randomized order: walking at 5 km·h(-1), +20%; running at 6 km·h(-1), +15%; and running at 8 km·h(-1), +10%. During the three trials, energy cost was assessed using an indirect calorimetry system and spatiotemporal gait parameters were acquired with a floor-level high-density photoelectric cells system...

Aerobic power (VO2max), aerobic capacity (RCP), and running efficiency (RE) are important markers of aerobic fitness. However, the influence of the angiotensin converting enzyme (ACE) polymorphism on these markers has not been investigated in healthy individuals. One hundred and fifty physically active young men (age 25 ± 3 years; height 1.77 ± 0.06 m; body mass 76.6 ± 0.9 kg; VO2max 47.7 ± 5.5 ml·kg-1·min-1) visited the laboratory on two separate occasions, and performed the following tests: a) a maximal incremental treadmill test to determine VO2max and RCP, and b) two constant-speed running tests (10 km·h-1 and 12 km·h-1) to determine RE...

The aim of the study was, in runners accustomed to speed endurance training (SET), to examine the effect of increased and maintained frequency of SET on performance and muscular adaptations. After familiarization (FAM) to SET, eighteen male (n=14) and female (n=4) runners (VO2-max: 57.3±3.4 ml·min(-1); mean±SD) completed twenty sessions of maintained low-frequency (LF; every fourth day; n=7) or high-frequency (HF; every second day; n=11) SET (intervention period; INT). Before FAM as well as before and after INT, subjects completed a series of running tests and a biopsy from m...

The prevalence of a sedentary (SED) life style combined with calorically rich diets has spurred the rise in childhood obesity which, in turn, translates to adverse health effects in adulthood. Obesity and lack of active (ACT) lifestyle may increase susceptibility to air pollutants. We housed 22 day-old female Long-Evans rats in a cage without (SED) or with a running wheel (ACT). After 10 weeks the rats ran 310 ± 16.3 km (SEM). Responses of SED and ACT rats to whole-body O3 (0, 0.25, 0.5, or 1.0 ppm; 5 hr/day for 2 days) was assessed...

PURPOSE: The Clara cell protein CC16, secreted from Clara cells in the lung, is discussed as a potential biomarker for toxic effects on the airways. An increased concentration of CC16 in serum may be caused by increased permeability of the lungs. To investigate the changes in P-CC16 in response to an intense exercise bout performed at different times of day (9 am and 4 pm) of highly trained individuals. METHOD: Using a crossover randomized design, 8 runners (mean VO2max 71 ml kg(-1) min(-1), SD 6) performed a 10-km time trial run, at 9 am and 4 pm, in an environmental chamber set at 6 °C...

AIMS: Impact activities like running are known to elicit symptoms of stress urinary incontinence (SUI). The aim of this study was to investigate and compare pelvic floor muscle activity in continent and SUI women during running at three different speeds and thereby elucidate contraction characteristics of the pelvic floor during impact. METHODS: Surface electromyographic (EMG) activity from the pelvic floor muscles during running on a treadmill was recorded with a tripolar vaginal probe...

Glacial fronts are important summer habitat for narwhals (Monodon monoceros); however, no studies have quantified which glacial properties attract whales. We investigated the importance of glacial habitats using telemetry data from n = 15 whales tagged in September of 1993, 1994, 2006 and 2007 in Melville Bay, West Greenland. For 41 marine-terminating glaciers, we estimated (i) narwhal presence/absence, (ii) number of 24 h periods spent at glaciers and (iii) the fraction of narwhals that visited each glacier (at 5, 7 and 10 km) in autumn...

BACKGROUND: The transport of pregnant women to an appropriate health facility plays a pivotal role in preventing maternal deaths. In India, state-run call-centre based ambulance systems ('108' and '102'), along with district-level Janani Express and local community-based innovations, provide transport services for pregnant women. We studied the role of '108' ambulance services in transporting pregnant women routinely and obstetric emergencies in India. METHODS: This study was an analysis of '108' ambulance call-centre data from six states for the year 2013-14...

The aim of this study was to compare the spatio-temporal parameters of trained runners and untrained participants with the same foot strike pattern (rearfoot) during running at controlled speeds. Twenty-one participants were classified in two groups according to their training experience: Trained (n=10, amateur runners with long distance training experience) and Untrained (n=11, healthy non-trained participants). Anthropometric variables were recorded, and the participants performed both a submaximal (between 9 and 15 km·h) and a graded exercise running test (from 6 km·h until exhaustion) on a treadmill...

The present study attempts to assess changes in soccer players' physical activity profiles under the simultaneous influence of the different combinations of ambient temperature and relative humidity characterising matches of the 2014 FIFA World Cup hosted by Brazil. The study material consisted of observations of 340 players representing 32 national teams taking part in the tournament. The measured indices included total distances covered; distances covered with low, moderate, or high intensity; numbers of sprints performed, and peak running speeds achieved...

PURPOSE: Faster heart rate recovery (HRR) following high-to-maximal exercise (≥90% HRmax) has been reported in athletes suspected of functional overreaching (f-OR). This study investigated whether this response would also occur at lower exercise intensity. METHODS AND RESULTS: HRR and rate of perceived exertion (RPE) responses were compared during an incremental intermittent running protocol to exhaustion in twenty experienced male triathletes (8 control and 13 overload subjects led to f-OR) before (Pre), immediately after an overload training period (Mid) and following a 1-week taper (Post)...

PURPOSE: Increases in cfDNA concentrations have recently been demonstrated to occur in a variety of exhausting and vigorous exercise settings. Here we assessed the association of cfDNA with exercise duration and intensity in a controlled test-retest setting of a regenerative up to moderate aerobic run. METHODS: In a pre-test the lactate threshold (LT) was determined in 13 subjects (range: 10.8-13.4 km/h) by means of a step-wise incremental running test. Speed of the two endurance runs was set to 9...

The performance and sex differences of long-distance triathletes competing in 'Ironman Hawaii' are well investigated. However, less information is available with regards to triathlon races of the Ironman distance held under extreme environmental conditions (e.g. extreme cold) such as the 'Isklar Norseman Xtreme Triathlon' which started in 2003. In 'Isklar Norseman Xtreme Triathlon', athletes swim at a water temperature of ~13-15°C, cycle at temperatures of ~5-20°C and run at temperatures of ~12-28°C in the valley and of ~2-12°C at Mt...

The assessment of aerobic endurance is important for training prescription in soccer, and is usually measured by straight running without the ball on a track or treadmill. Due to the ball control and technical demands during a specific soccer test, the running speeds are likely to be lower compared to a continuous incremental test. The aim of the present study was to compare the heart rate (HR), rating of perceived exertion (RPE) and speeds corresponding to 2.0 mmol∙L(-1), 3.5 mmol∙L(-1), lactate threshold (Dmax method) and peak lactate determined in the laboratory and in the Hoff circuit soccer-specific test...

This study investigated end-game and transient changes in running activities and whether these were concomitantly associated with reductions in skill-related performance in senior international rugby union match-play. Altogether, 18 official matches were analysed (322 individual observations) using computerised video-based tracking and event coding (Amisco Pro(®), SUP, Nice, France). In forwards and backs, trivial to small reductions (% difference: -2.1, ±1.3 to -10.0, ±4.0%) in total distance and that covered at high speeds (>18...